Modifications so far include:
In this page I detail the modifications I have done so far to my 1992 Mazda MX5 Eunos Roadster. The car is apparently a japanese import...(I say apparently because according to the DVLA's records, it's UK spec!)
So far the new clutch is struggling to cope with even the modest gains associated with freeing up the inlet and exhaust tracts. I would STRONGLY recommend that anyone thinking of tuning their MX5 should fit a racing paddle clutch (have a look at http://www.2kracing.com/index.php/cPath/6_93_1237), as standard clutches just don't cut the mustard past 140bhp...god only knows how much it would slip with another 50% horsepower and torque! This is the only time MX5 parts have let me down - I was advised that their own turbocharged MX5 ran one of the clutches I have, but if that's the case, it wasn't built to be thrashed as mine is..... the clutch slips between changes when you hit the gas at even a modest 5000 RPM, and the only way to get back to full grab is to back off the throttle!
The air scoop gives LOTS of cold, fresh air directly to the K&N filter (not a fully pressurised system yet, but I'm working on it) , and has been designed by myself to force air into the filter giving a supercharging effect at speed, and to lower the temperature in the engine bay by a considerable amount. The scoop delivers cool air far in excess of that required by even a high boost turbo or supercharger (intake area is 180cm2). Temperature around the filter housing (using digital thermometer) has dropped to 5 degrees above ambient @ 60mph, a significant improvement from the situation before (mx5's typically run at around 20 - 40 degrees above ambient at the filter due to the situation of the air flow meter just above the exhaust manifold....not good for producing power!). The ECU seems to cope with the vast increase in cold airflow around the filter fine, and the only ill effect seems to be increased fuel consumption due to extra power/torque produced, and the fact the car now wants to be driven harder everywhere (yippee!)
As this is a 1992 car, it is not required to have a Catalytic Converter fitted, so this has been removed, and a CAT bypass pipe substituted. This has pushed the torque produced up by around 10 ft/lb in the lower midrange, and is a good compliment for the K&N induction kit. Unfortunately there is no more power at the top end of the rev range, and the standard power step at 4,500 rpm has disappeared (due to more low end torque). Despite this, this mod is Recommended - the sound is addictive too!
Anyone thinking of fitting Eibach springs in conjunction with KYB shocks....DONT!! These springs are far too low and soft for even moderate race use, and are absolutely no use for bumpy roads. I have had to modify my front arches so that the 16X195 tyres don't foul over bumps....carrying a passenger over anything less than tabletop smooth roads is a joke until you do this! Get a balanced Koni or such like kit instead - the few pounds more is well worth the ride and roadholding, and ensures your chassis does not ground out on our potholed roads!
Planned further mods:
Well...Summer is supposedly here, and the Greddy kit is on it's way. The MX5 survived an outing around Knockhill race Circuit and is currently awaiting installation of turbo kit, intercooler and uprated fuel pump as well as a new Koni Sports suspension kit from those lovely people at MX5parts.co.uk. Hopefully that should stop the tyres trying to claw their way through the arches despite a full day's setup of the suspension!
Click HERE for .avi file
Well it was a long time coming, but the turbo kit is here from the States....it's a hybrid T25/T28 turbo with ENORMOUS 75mm intercooler. Had to cancel the Greddy kit, as ran out of cash at the time (like you do!) but the replacement is even better - same turbo as the FM11 kit with potential for a lot more power I think. Manifold is not very inspiring (cast, and has lots of nasty cast marks inside), but will be well ported before being fitted. As soon as I can source some piping for the intercooler and exaust that is (going to make these as it's not a standard kit....)! Scooby boys, you'd better start hiding now!
Finally got round to starting the Turbo install. It's been quite a nightmare as all of the pipework has had to be designed and made from scratch as this is a non-standard setup (T25/T28 turbocharger and 75mm intercooler off a Supra by the looks of it!)
Below are some pics of the install so far...I've also had to make up a full stainless exhaust system, as could not get hold of one to fit this turbo anywhere on the planet. Good job I'm an Engineer I'm thinking....
Well....the turbo is fully working and producing stupid amounts of torque and horsepower - so much that I have not stopped grinning since I got the beast on the road last night! The clutch is now the big weak point - starts slipping at 3,500rpm and gets progressively worse the more you push the accelerator. Jackson racing item or ACT clutch needs to be sourced and installed next!
Well.....Everything was going fine with the turbo beast when one morning in heavy rain I aquaplaned it into a tree at around 50mph....
Remember kiddies...never cook your tyres at the track and then go fast on the road in the pissing rain when you know you have not a lot of tread left. Doh!
R.I.P. THE BEAST.
I now have another Eunos, this time V-spec in green and have fitted the turbo kit. Pics and stuff when I get time in between all the ebaying of bits....
Well a frantic install and all is looking good - the new car seems faster and more powerful than the old (which is nice!) and it must already have a decent clutch fitted as it doesn't slip with the turbo on full boost!
All I have to do now is respray the hardtop etc to match and get some decent tyres on the Enkei alloys to avoid another car/tree interface incident!
Well I know it's been a long time...pressures of work and all that!
I'll be writing a proper website when I can fit it in, but in the meantime just a quickie...
Just fitted a manual boost controller to the Mazda... sheesh! Well I can report that a standard engine will indeed run at 1 bar boost (14.7psi) without melting and gives silly amounts of wheelspin in 4th gear! You have to admire whoever designed the engine in the Mk1 - it really is bomb proof and a testiment to good design.
Naturally, I will be lowering the boost to a sane level before I use the car again on a public road ;-)
Apologies... another long spell of not doing anything with this website!
Hmm well I managed to blow up the motor on the 1.6... really hot day, 95 octane fuel and a race with a Supra did not do the engine too much good at all! Actually the problem has been tracked down to the middle 2 bores... rings stuck in pistons - this pressurised the block and blew the top off the radiator! This was in turn caused by overfuelling after fitting a new high flow fuel pump (as the old one was failing). Someone (ahem!) forgot to reset the AFPR to compensate!
While the lump was out, I skimmed the 1.6 flywheel and put this on the 1.8 engine, and fitted a new 6-puck racing clutch. Early indications are that this should be able to take the increased torque of the 1.8 engine with a good amount of boost, but until it is fully run in I won't be certain. Only problem with the new clutch is that I now have to behave like a hooligan at the lights to pull away as it is very grabby. Oh well :)
Here are some pictures of the new 1.8 litre Mk2 engine after it was shotblasted and treated to a serious amount of cleaning / loving care with new belts all round and a lick of paint...!
The engine is now fitted, and running well. I had to make a lot of modifications to various things to get the engine to run with the 1.6 ECU - if you are interested in what you need to do for a 1.8 engine swap then there is a lot of information available on the web about this... just do a Google search for 'miata 1.8 engine swap'.
Here are some pics of Al's 1992 Eunos, complete now with some decent wheels! These are Oz racing SuperLeggera's, fitted with Toyo Proxies
Mods so far:
